japonica vs Camellia japonica

japonica and Camellia japonica both are nouns.

Word	Noun	Adjective	Verb	Adverb
japonica	Yes	No	No	No
Camellia japonica	Yes	No	No	No

As nouns, japonica and Camellia japonica are synonyms defined as:

japonica and Camellia japonica: greenhouse shrub with glossy green leaves and showy fragrant rose-like flowers; cultivated in many varieties

japonica (noun)	Camellia japonica (noun)
deciduous thorny shrub native to Japan having red blossoms	greenhouse shrub with glossy green leaves and showy fragrant rose-like flowers; cultivated in many varieties
greenhouse shrub with glossy green leaves and showy fragrant rose-like flowers; cultivated in many varieties